In the last t went y yea rs i nter n et h as changed the human life in several aspects, different in ter net tools (email, forums, blogs ...) allowed new forms of social interaction and communication among people. At the beginning of the century the evolution of the internet-based applications allowed a new way of using the web. The internet became a platform where the contents are published and continuously modified by the users in a participatory fashion. This new way of creating and exchanging user-generated content on the internet was called Web 2.0 and the Social Media are the internet applications that allow it (Kaplan & Haenlein, 2010). Among the social media one of the most used subcategory are the online social networks (e.g., MySpace, Facebook). These sites attracted the social scientists' attention because of their large diffusion and their socia l a nd psych ol ogical impact. Searching in the PsychINFO database (on 28 May 2014) we found 177 publications containing the word 'MySpace' in the abstract, 506 containing 'Twitter', and 1249 containing the word 'Facebook'. Of course, the specific medium is not irrelevant because every social networking site has particular features. Nevertheless, there are similarities and the majority of the studies focused on Facebook (FB) because it is the largest one with over 1 billion active users in 2013.New technologies and social media are used particularly by young people (Holzner, 2009) but from the beginning of the Web 2.0 the situation is changing with the spread of this service to larger groups of users. Concerning FB in 2010, the fastest growing group of users was the one in the age group of over 34 years (Wilson, Gosling, & Graham, 2012). There are contrasting opinions on the positivity of social media. Some stress the new opportunities they offer, others consider them as just another aspect of the so-called liquid modernity (Bauman, 2000). Anyway, the fact is that at present they are a social phenomenon involving a great part of the population of the rich countries. For instance, in Italy in 2013, 44.3% of the entire population had a FB profile (Censis, UCSI, 2013).The Social Networking Sites and the Actual Social RelationsThe creators of the social networking sites define them as social utilities helping people to communicate with their friends and acquaintances. According to Wilson and colleagues (2012),19% of studies on FB examined the motivation of using it. The main motivations identified are the desire to keep in touch with friends (Bosch, 2009; Ellison, Steinfield, & Lampe, 2007; Lewis & West, 2009; Pempek, Yermolayeva, & Calvert, 2009; Sheldon, 2008) and to meet new people (Ellison, Steinfield, & Lampe, 2007; Sheldon, 2008; Urista, Dong, & Day, 2009; Zhao, Grasmuck, & Martin, 2008). The first one is justified by the opportunity the medium offers to manage off-line social networks and by the social pressure to use the medium because many other people do it. The second may be related to the need of minimizing loneliness. Among social scientists there are two different positions concerning the effects of social networking sites on social interactions (Kujath, 2011). One position is that virtual relations are a surrogate for face-to-face interactions and they are deteriorating relationship quality. Weak mediated ties are substituting for strong direct ties. The other opinion is that social media could be a useful tool to maintain and expand upon direct social networks. Some authors even affirmed that FB may be a source of social capital (Ellison, Steinfield, & Lampe, 2007). The expansion of social network should lower the feeling of loneliness but research showed that the relation between FB use and loneliness is not univocal and depends on the specific activity that users participate in on the social networking site (Burke, Marlow, & Lento, 2010; Wise, Alhabash, & Park, 2010). People with different feelings of loneliness seem to use FB in different way, not more or less. …